The electronic configuration of an element is 1\(s^2\) 2\(s^2\) 2\(p^6\) 3\(s^2\) 3\(p^3\). Where is the element located in the periodic table?
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(C)
Group V, period 3
2
Group O of elements are unreactive because
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(B)
their highest occupied enegy level is full
3
An element X with electronic configuration \(1S^22S^22P^63S^2\) combines with another element Y with the configuration \(1S^2S^22P^23S^23P^5\). What is the formula of the compound formed?
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(D)
XY2
4
Which of the following statements about dative bonding is not correct?
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(C)
each participating atom contributes one electron
5
Which of the following quantities is the same for one mole of Br2(l) and one mole of He(g)?
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(A)
Number of molecules
6
Which of the following acids is dibasic?
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(B)
Trioxosulphate (IV) acid
7
Bees inject an acidic substance when they sting. Which of the following chemical could be used to treat bee stings?
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(B)
NaHCO3
8
Which of the following salts can be prepared by reacting the metal with dilute H2SO4?
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(B)
MgSO4
9
Which of the following solutions will give a precipitate with dilute tetraoxosulphate (V) acid? l. Lead (ll) trioxonitrate (V) solution ll. Barium chloride solution lll. Sodium chloride solution
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(C)
l and ll only
10
Substance Q reacts with cold water to form a solution which turns red litmus blue. Substance Q could be
Răspuns
(D)
sodium
11
What term is used to describe an oxide whose aqueous solution turns blue litmus red?
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(B)
Acid anhydride
12
The pH of 0.50 mol dm-3 solutions of HCI, H2SO4 and CH3COOH were measured. which of the following statements about the values obtained is correct?
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(D)
the pH value of the CH3COOH was the highest.
13
Which of the following processes involves neutralization?
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(D)
Liming of soil
14
Sea shells contain mainly CaCO 3. Calcium oxide can be prepared from sea shells by
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(B)
heating at a high temperature
15
Which of the following statements about an exothermic reaction is correct?
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(A)
the products have less heat content than reactants
16
A reducing agent is expected to
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(A)
decolourize acidified KMnO4 solution
17
Consider the electrochemical cell represented below Zn(s)/Zn2+(aq)//Cu2+(aq)/Cu(s). Which of the following equations describes the reaction occurring in the cell?
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(C)
Zn(s) + Cu2+(aq) →Zn2+(aq) + Cu(s)
18
Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals cannot displace Y from an aqueous solution of its salt?
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(D)
Z
19
Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals is most likely extracted by the electrolysis of its fused chloride?
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(A)
V
20
Which of the following statements is/are correct about tin plating? l The electrolyte must be a soluble salt of tin ll. the objective to be plated is made the cathode lll. The anode is made of tin lV. The negative electrode dissolves
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(C)
l,ll and lll only
21
Determine the amount of electrons needed to deposit 6.4g of copper during the electrolysis of copper (ll) tetraoxosulphate (IV) solution [Cu = 64]
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(B)
0.20 mole
22
A given fuel has an octane number of 100. This means that
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(A)
the knocking tendency of the fuel is low
23
The equation for the reaction at the anode during the electrolysis of concentrated sodium chloride solution is
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(A)
2CI-(aq) → CI,sub>2(g) + 2e-
24
Which of the following compounds has the same empirical formula as benzene?
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(A)
C2H2
25
A given fuel has an octane number of 100. This means that
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(A)
the knocking tendency of the fuel is low
26
Wine containing 8% to 17% ethanol can be converted to gin containing about 40% ethanol by
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(B)
distilation
27
Which of the following substances could be responsible for the banana taste of a food flavour?
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(D)
Pentylethanoate
28
What is the organic product of the reaction of C2H 5OH with excess acidified K 2Cr 2O7(aq)?
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(A)
CH3COOH
29
The reaction of vegetable oil with a solution of wood ash is
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(A)
saponification
30
What process does the following equation represent ? n(C\(_{6}\)H\(_{10}\)O\(_{5}\)) + nH\(_{2}\)O → nC\(_{6}\)H\(_{12}\)O\(_{6}\) ?
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(B)
Hydrolysis of starch
31
When excess ethene is shaken with acidified KMnO4 solution, the product obtained is
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(C)
ethane - 1, 2 - diol
32
What volume of 0.20 mol dm -3 NaOH solution would yield 5.0 g of NaOH on evaporation to dryness? [NaOH = 40g mol-1]
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(B)
625 cm3
33
Which of the following compound is used for removing impurities from bauxite?
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(A)
NaOH
34
What is the main impurity in haematite?
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(C)
SiO3
35
When a sample of water was boiled, it lathered more readily with soap. it can be concluded that the sample most likely contained
